TalkChess.com

I see that TCEC now uses Dual 2699v4, which strongly suggests that the secret to CCC is "cores, cores, cores"

ouachita wrote: ↑Sat Sep 15, 2018 8:08 pm I see that TCEC now uses Dual 2699v4, which strongly suggests that the secret to CCC is "cores, cores, cores"

There's no secret. Overall search speed is a function of clock speed multiplied by core count, allowing for search inefficiency as core count increases.

The fastest systems will have many cores running quickly.

... it would one with a Ryzen Threadripper 2950X in it.

Werewolf wrote: ↑Sat Sep 15, 2018 10:37 pm

ouachita wrote: ↑Sat Sep 15, 2018 8:08 pm I see that TCEC now uses Dual 2699v4, which strongly suggests that the secret to CCC is "cores, cores, cores"

There's no secret. Overall search speed is a function of clock speed multiplied by core count, allowing for search inefficiency as core count increases.

The fastest systems will have many cores running quickly.

Assuming core scaling is not at issue, the more cores (Intel or AMD) the better, e.g., [Dual CPU] Intel Xeon Platinum 8168 @ 2.70GHz (48 cores) ??

Depends on what you want. If you want the highest number of games completed in the shortest time than more cores is better. If you want the fastest analysis on a single engine then fewer cores but higher core frequency is better.

tpoppins wrote: ↑Sun Sep 16, 2018 2:10 am Depends on what you want. If you want the highest number of games completed in the shortest time than more cores is better. If you want the fastest analysis on a single engine then fewer cores but higher core frequency is better.

Correspondence chess - devote ~95% of the CPU's resources to one program, the engine, to reach the greatest depth of analysis of one position in varying amounts of time, but often measured in hours, depending.

My system is an Intel i7-5960X with 8 cores, all overclocked to 4.6 GHz. 128 GB of RAM overclocked also.

That CPU was about $1000 when I got it. If you forego the over-the-top-GPU and just get a Corsair H100i cooler for it, your entire build will be under $3000.

Even at the stock speed of 3.0 GHz the i7-5960X is a damn fast chip. It's getting a bit dated now, but my benchmarks with it still outperform 99% of all of the published ones I have seen. I was the #1 on Fritzmark for a few years.

Threadripper 2990wx (32 core/64 thread) or 2950x (16 core/32 thread) are looking very good - at least in term of perf/$:
E.g: see stockfish benchmarks at the bottom of the page:
https://www.phoronix.com/scan.php?page= ... 90wx&num=5

ouachita wrote: ↑Sun Sep 16, 2018 1:43 am

Werewolf wrote: ↑Sat Sep 15, 2018 10:37 pm

ouachita wrote: ↑Sat Sep 15, 2018 8:08 pm I see that TCEC now uses Dual 2699v4, which strongly suggests that the secret to CCC is "cores, cores, cores"

There's no secret. Overall search speed is a function of clock speed multiplied by core count, allowing for search inefficiency as core count increases.

The fastest systems will have many cores running quickly.

Assuming core scaling is not at issue, the more cores (Intel or AMD) the better, e.g., [Dual CPU] Intel Xeon Platinum 8168 @ 2.70GHz (48 cores) ??

Of course, if you can afford it.

Here is a formula for calculating search speed which worked about 8 years ago when Rybka was dominant and Intel's Nehalem was the top CPU.

Search speed = processor efficiency x clock speed x number of cores to the power of 0.76

So, which is better, a Quad core @ 4.0 GHz or a Six core at 3.5 GHz?

Quad: 1 x 4.0 x (4^0.76) = 11.47
Six core: 1 x 3.5 x (6^0.76) = 13.7

So the six core is about 20% faster in this case.

The formula no longer holds true today because CPUs are a bit more efficient (I reckon Intel's Haswell added about 14% and all generations after it hold that value - others may disagree) and also, more importantly, modern engines have a different type of search called Lazy SMP which is better at using more cores.

But the idea is still valid, the number just need updating to apply to Stockfish.

Perhaps the speed of Intel's latest 18 core would be:

1.14 x 4.2 x (18^0.8) = 48.3

AMD Threadrippers are better value for money, though in my opinion a dual socket Intel system from eBay from a few years ago could be faster and cheaper.

AMD Ryzen Threadripper 2990WX might be the way to go.